<input type="button" id="saveBtn" value="save" />
<input type="button" id="backupBtn" value="backup" />
<script type="text/javascript">
    $("#saveBtn").click(function() {
        $.post(
            'http://localhost/ci/index.php/welcome/insert',
            {},
            function () {
                alert('called');
            }
        );
    });
    $("#backupBtn").click(function() {
        $.post(
            'http://localhost/ci/index.php/welcome/backup',
            {},
            function () {
                alert('called');
            }
        );
    });
</script>